Telephone-switch.



no. 7|4,54o. Patented Nov. 25, 1902.

.1. A. WARRlC-K.

TELEPHONE SWITCH.

(Application mad Nov. 5, i901.

(No-Model.) w v 3 Sheetv-Shaat -l.

WITNESSES.-

ATTORNEYS J. vA. WABRICK. TELEPHONE swnca.

Application ma Nov. 5, 1901. (No ModaL') 3Sheets-Shegt 2.

A TTOHNEYS m: NORRIS PETEVRS cu. Puma-mum wnsnmemm o. c.

J. A. WARRICK. TELEPHONE swncu.

(Application filed liov. 5, 1901.) ([10 Model.) 3 Sheets-Sheet .3.

WITNESSES IN VENTOH ma gw 2 flz arrw WM I By ATTORNEYS NITE JOHN A. WARRIGK, OF SHELDON, ILLINOIS.

TELEPHONE-SWITCH.

SPECIFICATION forming part of Letters Patent N 0. 714,540, dated November 25, 1902.

Application filed November 5, 1901. Serial No. 81,162. (No model.)

To all-whom, it may concern:

Be it known that I, JOHN A. WARRIOK, a citizen ofthe United States, and a resident of Sheldon, in the county of Iroquois and State of Illinois, have invented a new and Improved Selective Apparatus for Telephones or theLike, of which the following is a full, clear, and exact description.

My invention relates to telephone-switches, and'more particularly to the type used on party-lines.

The object of the switch is to enable any two or more instruments upon such a line to be brought into use without molesting other instruments upon the same line. While the switch might be used to advantage with many electrical instruments, my chief idea is to use it upon the kind of party-lines in which there is no central stationand where each subscribermay call up any other subscriber upon the line and talk to him without interference from any source. The switch is, however, applicable also to party-lines having a central station. I also desire to lessen the resistance in the circuit and to prevent piracy of the telephone messages. By my system any reasonable number of telephones may be placed in the samecircuit and any subscriber may select and talk to any other pose of actuating a revoluble disk 0.

subscriber without danger of eavesdroppers hearing what is said. Furthermore, codesignals are not necessary with my system.

In the accompanying drawings like letters and figures of reference indicate like parts in all the views.

Figure 1 is an elevation of the switch. Fig. 2 is a section upon the line 2 2 of Fig. $100king in the direction of the arrow. Fig. 3 is a section upon the line 3 3 of Fig. 1 looking in the direction of the arrow. Fig. 4 is a diagram showing a telephone-office using my system. Fig. 5 is adiagram showing several of my switches in actiomand Figs. 6 and 7 are detail views hereinafter more fully described.

The switch proper will first be described, and then itsmethod of connection with the system audits Inodeof operation will be explained.

Upon a base-board a, provided with a bearing-post a, is mounted a train of springdrivenclockwork I), wound at b for the pur- This disk is provided upon its inner face with pins (1 and upon its outer face with notches f, the number of pins corresponding withthe number of notches less one. The notches are provided with numerals ranging from 1 to 11. The character zero is not provided with a notch. The movement of the disk 0 is restricted and governed by the escapement 6, provided with pallets t' and k. This escapement is adjusted by means of the spiral spring g, provided with an adjusting-screw g, and the esoapement is actuated by means of the electromagnet h, which is normally connected with the main line. When the electromagnet h is excited by a current, the escapement cis drawn downward, thus allowing one of the teeth to pass from the pallet '11 to the pallet k, the space traversed by the disk representing one-half of the distance between two consecutive pins-that is to say, a pin 01 first lodges against the pallet '5, and. as the escapement falls this same pin lodges against the pallet 76, and upon the release of the escapement another pin 01 lodges against the pallet t', and so on, each pin striking the escapement twice before moving on. By this means the disk 0 can be actuated at will by throwing currents into the mainline, so as to intermittently excite the magnet h. Mounted adjacent to the face of the disk is a hollow knob m, provided with an arm Z, rigidly connected therewith, said arm being provided with a single boss 0". A spring a, coiled on an extension of the shaft of the disk aim the hollow hub m, normally holds the knob and its arm Z close to the face of the disk. By pulling the knob outward slightly, however, the boss 0 is disengaged from the disk, so that the arm Zcan be moved radially around at will. Upon the base-board a is mounted a rigid post 8, provided with an overhang s, located a slight distance from the edge of the disk, so that the arm Z can easily pass under the overhang if the boss isinone of the notches f, yet will not permit the arm Z to pass unless the boss 0 is thus engaged. The arm can never pass the overhang, therefore, except when close to the disk. By this means each subscriber by moving his knob can turn the arm around at will; but the arm cannot pass under theoverhang without causing it to engage and move the disk. Spring-contacts p q r are arranged upon the posts, as shown in Fig. 3,and the arm lis provided with a rounded face Z, (see Fig. 4,) which is free to disengage the contact 1) from the contact q and to cause connection between the contact 19 and contact r. This change of contacts occurs every time the arm Z is moved under the overhang.

Supposing now that several stations are established, as shown in Fig. 5, and that subscriber No. 1 on the left desires to communi cate with some one of the other subscribers say the one on the right-No. 4. To do this, subscriber No. 1 moves the arm Z to the numeral 4 on the disk 0 and causes the boss 0 to enter the notch f, adjacent to the numeral 4. He then by means of his magneto sends a series of excitations through the main line, thus actuating all of the electromagnets h at the same time, thus causing the several magnets to rotate the several disks 0. The disks of course each rotate one step at a time, and of course it is an easy matter for subscriber No. 1 to cause all four of the disks to turn a distance represented by fournumerals. The result is that as he places his arm Zupon the numeral 4 and as subscriber No. 4 normally keeps his arm upon his proper numeral,

which is 4, the same degree of revolution is necessary in the two disks to bring the two arms under their respective overhangs at the same time. When this is accomplished, subscriber No. 1 is in communication with subscriber No. 4 and subscribers Nos. 2 and 3 are not disturbed. The bell of subscriber No. 4 soon rings automatically and is the only bell that answers, as will be described later on.

Suppose now that subscriber No. 2 Wishes to listen to the conversation carried on between subscribers Nos. 1 and 4. Subscriber No. 2 can of course move his arm Z around overthe disk c,buthe cannot get the arm under the overhang in any manner except to cause it to engage one of the notches and move his disk. In doing this he moves the disks of the subscribers who are talking and throws them out of connection with each other. It is therefore impossible for another subscriber to listen to any conversation, for the reason that in throwing his instrument into connection subscriber No. 2 throws out of connection the instruments which are used in talking. If subscriber No. 1 wishes to talk, say, to subscribers No. 3 and No. 4, he calls them separately and instructs them how to arrange the respective arms upon their respective disks, which being done he can talk with the two at the same time. Any number of telephones can thus be connected up.

It will be understood, of course, that each subscriber has aparticular numeral and that his arm Z is normally adjacent to said numeral. He only moves the arm from his numeral to call a desired number, and when he is through talking he moves his arm back to his own numeral. After using the telephone each subscriber sees that his arm is placed upon his proper number,.and some one of the subscribers actuates the electromagnets until all of the disks are restored to their normal position say with the zero down adjacent to the overhang, as shown at the left in Fig. 5.

It Will be understood that the number of subscribers is commensurate with the number of numerals used upon the disk. If the number of subscribers be smaller than the number of numerals, of course some of the numerals are virtually idle and the arms are simply passed over them to the numerals representing the subscribers. The clockwork may be omitted where the work upon the line is light.

These instruments are preferably connect ed up as follows: Supposing the line-wires enter an office through the binding-posts 1 and 8. The currents for actuating the magnets may be supplied from any source, such as a magneto M, as shown in Fig. 4. It matters not whether the magneto generates an alternating or a continuous current, although the continuous current is preferable. I prefer to use the magneto for generating the current to move the magnets and for this purpose only. For signaling I prefer to have a separate electric bell A, well known in the art as a short-circuit bell,actuated by local batteries B B and set to ring after the circuit has been completed for a predetermined period. Examples of such bells are de scribed, for instance, in the United States Patent No. 548,904, dated October 29, 1895, to Badt,or in the United States patent to Rhodes, No. 276,286, dated April 24, 1883. Bells of this type are often used in connection with gaslighting. The ringing of the bell A, therefore, is accomplished by the local batteries B B, the ringing-circuit being switched out of the main line when each subscriber takes down his receiver.

Suppose now that subscriber No. 2 is called. His arm Zwill be placed in the position shown in Fig. 4 by the pulsations sent through his electromagnet. The current traversing the contacts 19 Q will be broken and will pursue the course 19 r. The effect is that the bell of subscriber No. 2 to call the subscriber rings by being actuated by the local battery. Subscriber No. 2 now takes down his receiver, which has the effect of throwing his hell out of circuit and of throwing his secondary coil into the main-line circuit and his primary coil into the battery-circuit, as is the case with ordinarytelephonesystems. He isnowready for conversation. Apush-button K is pressed against the contact 1) and disengaged from the contact tt by the operator when he de sires to call any other subscriber. The contacts w x y 2 upon the receiver-hook are arranged in the usual manner relative to the other parts of the apparatus.

The different main and local circuits are as follows: Supposing that the disks are in any of the positions shown in Fig. 5, the circuit is as follows, (see Fig. 4:) from the binding-post 5, push-button K, contact to, and wire 7 to the binding-post 8. A portion of the current is shunted off and takes the following course, to wit: 2, 9, w, 5, 6, K, u, 7, and 8. If the push-button K be pressed to the left for the purpose of throwing the magneto-current into the main line, the circuit is as follows: from the binding-post 1, wire 2, receiver-hook 9, contact w, wires 5 and 6, contact 0, wire 16, magneto M, wires 17 and 7 to the binding-post 8. When one of the disks is in the position shown in Fig. 4 and has remained in said position for a predetermined interval, the local battery rings the bell through the following circuit: 13, 13, B, 12, 11, bell A, 10, 9, 2, 3, p, r, 15, 14, B.

When the receiver is taken from the hook, the circuit through the apparatus or so-called talking-circuit is as follows: from the hinding-post 1, wire 2, receiver-hook 9, contact y, wires 18, 19, and 20, secondary coil S, Wires 21, 5, and 6, push-button K, contact LL, and wire 7 to the binding-post 8. This removal of the receiver also establishes the battery: circuit as follows: from the binding-post 1, wire 2, receiver-hook -9, contact .2, wires 22 t and 23, primary coil P, transmitter T, wires 24 and 12, battery B, wire 13,. battery B, wires 14 and 15, contacts 7' and 19, wire 3 to the binding-post 1. It will be seen, therefore, that when the receiver is off the hook the transmitter is in a local battery-circuit disconnected from the battery. It will also be seen that the bell is not in the battery-circuit when the transmitter is being used in said circuit.

The object in omitting the notch from that part of the disk denominated zero is to have upon each disk some one point representing the vacant space which cannot be readily reached by the radially-moving arms because of its proximity to the overhang, the disks beingin their normal positions-that is to say, each arm can be swung around radially, but cannot readily make a complete circle because of the overhang being in the way at one point-and it is this idle point which is represented by the character zero. 1

It will be seen that I have invented a simple, efficient, and cheap switch which can be used upon a telephone system quite analogous to the ordinary system. and can be operated by people comparatively inexperienced. It will also be seen that my system is not liable to get out of order and that it possesses all of the advantages above described.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. A selective apparatus for telephones or the like, comprising a frame, a movable electrical contact located thereon, a revoluble disk provided with pins and with notches, means for actuating said disk, a magnet-controlled escapement provided with pallets for engaging said pins, and an arm loosely pivoted upon said disk, said arm being provided with a boss for engaging said notches and with a beveled end for engaging said contact.

2. A selective apparatus for telephones or the like, comprising a frame provided with an overhang, a revoluble disk mounted upon said frame and provided with notches, an arm centrally pivoted upon said disk and provided with a boss for engaging said notches, said arm being free to pass under said overhang only when said boss engages said notches, a movable electrical contact mounted upon said frame and in the path of said arm, and means for actuating said disk and said arm.

3. A selective apparatus. for telephones or the like, comprising a frame, a disk provided with a circle of notches interrupted by a blank space not provided with a notch and with a full circle of pins corresponding to said notches and said blank space taken together, an arm pivoted upon said disk and provided with a rounded end and with a boss for engaging said notches, a fixed overhang mounted upon said frame, said overhang being normally in the path of said arm but clearing the same when said boss engages one of said notches, and electrical mechanism for actuating said disk.

In testimony whereof I have signed my name to this specification inthe presence of two witnesses.

JOHN A. WARRICK. \Vitnesses:

G. H. GAY, CHAS. WARNER. 

